Solar-blind photodetectors based on MXenes–β-Ga₂O₃ Schottky junctions

Abstract

In this work, high-performance solar-blind photodetectors based on MXenes–β-Ga2O3 Schottky junctions have been developed by utilizing transparent conductive MXenes as the Schottky electrode of β-Ga2O3. Due to the high MXenes–β-Ga2O3 Schottky barrier, the photodetectors exhibit a rectification ratio as high as over 103 at ±2 V. At zero bias, the photodiodes show a responsivity of 12.2 mA W−1 at 248 nm and a detectivity of 6.1 × 1012 Jones, which are among the best values for β-Ga2O3-based solar-blind photodetectors working at zero bias. In addition, the Schottky photodiodes show a fast response speed with a rise time of 8 μs and decay time of 131 μs. Our results indicate that MXenes may be promising candidate for use as transparent conductive electrodes for UV optoelectronics.

Electrical Characterizations of Planar Ga2O3 Schottky Barrier Diodes

“…Owing to the low dark current and fast response speed [ 6 ], the Ga 2 O 3 -based Schottky diode photodetectors also have drawn much attention for high performances. For instance, the high photo responsivity (R), high external quantum efficiency (EQE), large specific detectivity (D*), and short response time in Ni/β-Ga 2 O 3 [ 7 ], Pt/ε-Ga 2 O 3 [ 8 ], graphene/β-Ga 2 O 3 [ 9 ], and MXenes/β-Ga 2 O 3 [ 10 ] photodiodes are realized.…”

Investigation of β‐Ga2O3 Film Growth Mechanism on c‐Plane Sapphire Substrate by Ozone Molecular Beam Epitaxy

“…[ 14 ] As for thin films, β‐Ga 2 O 3 can be prepared by either physical or chemical growth techniques. [ 15,16 ] Among them, molecular beam epitaxy (MBE) is a unique technology to grow β‐Ga 2 O 3 films, particularly to study the growth mechanism, due to its ultra‐high vacuum growth environment. Plasma‐assisted MBE is commonly used for oxide epitaxy, in which atomic oxygen (O) could be generated by radio frequency (RF) plasma activation.…”

Balancing the Transmittance and Carrier‐Collection Ability of Ag Nanowire Networks for High‐Performance Self‐Powered Ga2O3 Schottky Photodiode

“…High‐quality Ga 2 O 3 plays a vital role to guarantee the performance of the Ga 2 O 3 Schottky photodiode. [ 42 ] In this work, unintentionally doped β‐Ga 2 O 3 substrates with the orientation of () and electron concentration of 2.1 × 10 17 cm ‐3 were prepared for the construction of the AgNW–Ga 2 O 3 Schottky photodiodes. The phonon peaks at 170, 201, 321, 348, 416, 473, 658, and 767 cm ‐1 in the Raman spectrum of the prepared β‐Ga 2 O 3 ( Figure ) are consistent with previous reports.…”

“…To verify the spectral selectivity of the photodiode, the reaction of the device to near UV illumination (365 nm) with an intensity of 1.22 mW cm ‐2 is also tested, as shown in Figure 5c. This weak photocurrent of ≈2.6 nA, corresponding to the sub‐bandgap absorption by the intrinsic defects in the β‐Ga 2 O 3 substrate or the internal photoemission (IPE) effect of the Schottky electrode, [ 42,55 ] produces a R 365 nm of 5.7 µA W ‐1 and a rejection ratio ( R 254 nm / R 365 nm ) of 2.6 × 10 3 .…”